1. Field of the Invention
The invention concerns methods and devices to indicate when an animal is giving birth to its young.
2. Brief Description of the Prior Art
It will be appreciated that when horses, cattle, swine, and other animals give birth to their offspring, complications may develop which require the aid of the stockman or the veterinarian to prevent death of the newborn or for that matter, the mother. If the animal is not penned, it is common for the animal to attempt to hide during the birthing, complicating the problem of aiding the birth.
With the values which have been placed upon animals today in such cases as racehorses, milk cows, zoo specimens and the like, it is usual for an attendant to remain close to the animal at all times during the expected period of birthing. This may require maintaining all night vigils.
Obviously then, it is to the attendant's advantage to know exactly when, and if necessary, where an animal is, when the process of birthing begins.
The prior art literature is replete with descriptions of devices and methods for detecting the birth of newborn animals. For example, in the U.S. Pat. No. 4,232,686, apparatus for detecting the onset of parturition comprises three separate components to be mounted in three specific and different locations in respect to the vaginal orifice of the pregnant animal. Such apparatus has obvious limitations under certain circumstances. For example, an assemblage of the component parts in the proper locations is required. Unless this is accomplished properly, there is a high probability of a false triqgering of the indicator, or inoperability.
Also, the prior art apparatus such as the above-described prior art apparatus, may be difficult to assemble in the proper position, because its structure does not take into account the handedness of the individual making the assembly. For example, it can be fabricated to facilitate assembly by a right-handed or a left-handed individual, but not by both such individuals. Although this may sound like a trivial advantage, imagine a left-handed individual attempting to assemble apparatus designed for a right-handed operator, on the buttocks of a nervous 2,000 lb. animal.
Another disadvantage associated with prior art devices for monitoring parturition in pregnant females, particularly devices which include a switch and a remote control such as a bar magnet, is the occasional false triggering of a transmission (signal). The magnet must be placed within a certain range proximity to the switch to inhibit energizing the electrical circuit for a signal transmission. It is movement of the magnet component outside of the range of operation which closes the circuit. Unless one uses a very powerful magnetic force (usually equated with a large magnetic mass), the range of the remote control will be small and the distance between the reed switch and the magnet critically short, for maintaining the switch in an open position. A few millimeters distance can mean the difference between opening and closing the switch. False triggering of the signal can occur from simple movements of the animal, resulting in displacement of the magnet outside of the control range. This is particularly true for very active zoo animals or horses which are prone to rub against fixed objects to relieve the sensory perception associated with the presence of the device. The device of the present invention solves this disadvantage of the prior art, without increasing the mass of the magnet. The solution we found comprises placement of the magnet component as a remote control device, in a fixed position relative to the switch mechanism and immobile under ordinary conditions apart from actual parturition. False triggering of a signal is thus obviated.
Other advantages of the device of the invention will be apparent to those skilled in the art from the following description.